feat(sdk): P4.5 @insignia/iios-support-web (composes message-web + support REST)

SupportProvider (wraps MessageProvider + support client); useEscalate, useTickets/
useAssignedTickets (+createTicket/patch), useCallbackRequest, useAvailability;
re-exports useThread/useMessages. Boundary allowlist: support-web -> contracts+
kernel-client+message-web+inbox-web.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/iios-support-web/src/index.ts

@@ -0,0 +1,11 @@
+export {
+  SupportProvider,
+  useEscalate,
+  useTickets,
+  useAssignedTickets,
+  useCallbackRequest,
+  useAvailability,
+} from './react';
+// Re-export the chat hooks so a support app imports everything from one place.
+export { useThread, useMessages } from '@insignia/iios-message-web';
+export type { Ticket, TicketState, CallbackRequest, Message } from '@insignia/iios-kernel-client';